Indophenol dyes

2,6-Dichlorophenolindophenol (DCPIP, DCIP or DPIP) is a chemical compound used as a redox dye. When oxidized, DCPIP is blue with a maximal absorption at 600 nm; when reduced, DCPIP is colorless.

Indophenol is an organic compound with the formula OC6H4NC6H4OH. It is deep blue dye that is the product of the Berthelot's reaction, a common test for ammonia. The indophenol group, with various substituents in place of OH and various ring substitutions, is found in many dyes used in hair coloring and textiles.